MALT1 and diffuse large B-cell lymphoma: MALT1 is a driver oncogene in over 50% of mucosa-associated lymphoma and a subset of diffuse large B-cell lymphoma, which is attributed to gene amplification or chromosomal translocation with the apoptosis inhibitor 2 (API2) and immunoglobulin heavy chain loci.31, 32, 33, 34, 35, 36 These genetic changes lead to an increased expression of MALT1 or expression of the constitutively active API2-MALT1 fusion protein.